Abstract: An object sensor outputs an obstacle detection signal in response to passing of an obstacle. A central control unit reads a 2-dimensional image from an imaging unit in response to the obstacle detection signal. A detection area is obtained by subtracting a background image prestored in a memory from the input 2-dimensional image. The detected image on a 2-dimensional plane is transformed into image data in a 3-dimensional space. The CCU computes the projection area of the image data on an arbitrary plane in the 3-dimensional space. The object is discriminated by comparing the computed projection area with the projection area based on the reference value of the object prestored in the memory.

Abstract: An apparatus for monitoring a moving object comprises an image memory for storing a reference monitor image of a designated monitor region, a distance map memory for storing a distance map, the monitor image of the designated monitor region and the distance map comprising a plurality of blocks having distance data from a predetermined reference point in the monitor region to points corresponding to the blocks, an object image detector for detecting an object image based on an input monitor image of the designated monitor region and the reference monitor image read out from the image memory, and a distance detector for detecting a distance from the reference point to the moving object in accordance with the detected object image and the distance map read out from the distance map memory.

Abstract: A correlogram is initially prepared which represents a relation between the gross volume of all tries and the maximum gross weight of a motor vehicle. The maximum gross weight of the vehicle is one of important factors for determining a charge for a vehicle to be run on the toll road. In the method of this invention the outer diameter and rim diameter of the respective wheels of the vehicle are found through the processing of the side profile image of the vehicle as obtained by a TV camera. According to this invention the total volume of all the tires is calculated from the outer diameter, rim diameter, width and total number of the wheels. In this way, the maximum gross weight of the vehicle is calculated based on the correlogram.